Emergencies around the world are grabbing our attention and prompting action from our political leaders. The nuclear crisis in Japan has galvanised governments, from China to Germany, to review their own nuclear power programmes. The threatened humanitarian disasters in Libya and Ivory Coast have prompted military interventions from Nato and the United Nations. But when it comes to the most pressing international emergency of all, the destabilisation of the planet's climate through mankind's emissions of carbon dioxide and other industrial gasses, all urgency has drained away.

Today two stories underline the dangers posed by global warming. A consortium of European scientists is warning that the melting of Arctic sea ice could disrupt the North Atlantic Drift and the Gulf Stream. It is this current of water that ensures Britain has a mild, rather than an Arctic, climate. If the Gulf Stream is disrupted, these islands could experience winters as severe as northern Canada.

This is not certain to happen. But nothing is certain about the outcomes of this experiment we are performing on our planet's climate. All we know is that the more carbon dioxide we pump into our atmosphere, the greater the risk we run of dangerous consequences.

Another report today shows that the Arctic ozone layer exhibited unprecedented damage this winter, partly as a result of emissions of industrial chemicals. The ozone layer crisis was declared "solved" many years ago thanks to tighter regulation. But those chemicals that mankind pumped into the atmosphere in previous decades are still having an effect. This is a lesson in the dangerous delay in the impacts of environmental pollution. Like ozone-damaging chemicals, the full effects of the carbon we are sending into our climate at this moment will only be felt later this century.

If we were behaving rationally, our response to global warming would be just as urgent as it is to the threat of crimes against humanity in North Africa or the Middle East. The risk to life and prosperity is just as great. Yet we seem unable to focus on any crisis that does not threaten disaster in days or weeks.

Last year, David Cameron proclaimed that his Government would be the "greenest ever". But he has failed to live up to that pledge. Last month, George Osborne suspended the scheduled rise in fuel duty, even though this is one of the most effective "green" taxes because it encourages people to use less petrol.

This is not just cynicism from ministers. The general public do not hold politicians to account for their failure to meet environmental pledges. Nor is it an exclusively British disease. The story is the same abroad. There is depressingly little pressure from populations anywhere for action from their political representatives on global warming.

That needs to change. We need to understand that the sort of humanitarian crises we are witnessing now, and the climate emergency that looms later this century, have a connection. The revolts across the Arab world are linked to the world's thirst for fossil fuels. The West has propped up repressive regimes in the region because they have kept the oil flowing. Now those brutalised populations are fighting back. Cutting our dependence on fossil fuels would yield a humanitarian dividend.

There is another connection. Those same parts of the world that are in ferment now will feel the effects of climate change first. Global warming is already encouraging violent competition for water resources in Sudan. The present surge in refugees fleeing Africa for Europe is merely a foretaste of what is likely to come if we do not act to prevent runaway climate change. If we are to hand down a stable world to future generations, we need to focus not only on those emergencies that dominate the daily news headlines, but also the slow-motion disaster of global warming.